Nowadays, liquid crystal display (LCD) panels are widely applied to various electronic products with growth potential, such as monitors, notebook computers, digital cameras, and projectors. After manufacturers of LCD panels fabricate glass substrates, a color filter is firstly combined with the glass substrates, then liquid crystals are filled into the sealed glass substrates and the color filter, and further combined with various components, including a backlight module, driver ICs, controller PCBs, etc., to commonly construct a LCD module for selling to downstream manufacturers of notebook computers or LCD monitors.
The backlight module is one of the key components of LCD panels. Because the liquid crystals cannot emit light by themselves, the function of the backlight module is to provide evenly distributed light sources with sufficient brightness for normally showing images. The backlight module comprises various components, such as light sources, a lamp shade, a reflector plate, a light guide plate, a diffusion sheet, a brightness enhancement film, and an outer frame.
Refer now to FIG. 1, which is a cross-sectional view of a traditional backlight module. A traditional backlight module 90 comprises a plastic frame 91, a reflector 92, a light guide plate 93, an optical film assembly 94, a light source circuit board 95, and a plurality of point light sources 96 installed on the light source circuit board. In actual installation, there are still some problems existing in the traditional backlight module 90, as follows: when in assembling, the plastic frame 91 must install a light guide plate element and light sources in order, wherein the installing step of the light guide plate element comprises installing the reflector 92 in order, the light guide plate 93, and the optical film assembly 94 into the center of the plastic frame 91; and the installing step of the light sources comprises reversely installing the light source circuit board 95 having the point light sources 96 between a side edge of the plastic frame 91 and the light guide plate 93. Finally, light shading tapes (not shown) are used to fix the light source circuit board 95 on the surfaces of the side edge of the plastic frame 91 and the light guide plate 93 simultaneously. Thus, the point light sources 96 on the light source circuit board 95 can emit the lights toward the light guide plate 93.
However, when the above-mentioned assembling of the light sources and the light guide plate element is finished, a test is necessary to be processed. If anyone of the light sources or the light guide plate element is found to be defective, an additional test to find which parts the defect is from is necessary, so as to change the defective parts. However, the plastic frame installed with the light sources and the light guide plate element is a one-piece design, and the light source circuit board 95 is simultaneously fixed on the side edge of the plastic frame 91 and the light guide plate 93, so that in a repair and rework after the above-mentioned finding of the defective parts, the backlight module must be entirely disassembled to process the related test, parts changing, and reassembling operation. Therefore, this way not only lowers the efficiency, but also may cause the other normal parts to be damaged during the repeated disassembling and assembling processes.
Hence, it is necessary to provide a backlight module and a plastic frame structure thereof which solve the problems existing in the conventional technologies.